Nongelling lacquer



I 15 lacquer or agglomeration of a part of the lacquer been shownthat'the gelation is due at least in '20 be found in the gelled lacquer. In the case of of lactic acid will prevent gelation of bronzing Patented Aug. 22, 1933 I I I I I l NONGELLING LACQUER Charles Begin, 'Ierre Haute, lnd and Vaughn Kelly, Chicago, Ill., assignors to Commercial Solvents Corporation, Terre Haute, Ind, a Core peration of Maryland No Drawing. Application July 29,1931 Serial No. 553,847

14 Claims. (01. 134-79) The present invention relates to improvements malic acid was incorporated had not gelled at in nitrocellulose lacquers containing basic pigthe end of a two-months observation period, ments and esters of monohydroxy monocarboxwhereas those containing 'no malic ,acid had ylic acids. More specifically, the present invengelled or agglomerated badly in every case in 5 tion relates to a method for preventing gelling, less than a month.

livering or agglomeration of nitrocellulose lac- It has previously been known that malic acid quers containing basic pigments and solvents or a salt of malic acid will prevent the gelation such as the esters of lactic acid or oxyisobutyric of bronzing lacquers (copending application 418,- acid. 651 by Denis .J Burke) but this is an entirely-dif It has been known for some time that lacquers ferent phenomenon from that under consideracontaining basic pigments such as zinc oxide and tion in the present case. In the case of bronzing solvents such ethyl lactate or ethyl oxyisolacquers it is believed that the gel formation is butyrate are subject to a phenomenon which may due to the reaction of the metallic bronze with take the form of either gelation of the entire nitrocellulose, Whereas in the present case it has 0 into large particles, leaving the remainder of partto the reaction of the basic pigment with the lacquer as a liquid. The gelling or'livering the acid radical of the solvent employed. That of the lacquer is the more common of. the two these two phenomena areentirely different is forms, but evenin this case agglomerates may also shown by the fact that lactic acid or a salt lacquers containing relatively large amounts of lacquers,whereas these materials will definitely zinc oxide and lactate solvents the gelation often increase the tendency of lacquers of the type now takes place within a week after the preparation under consideration to gel. It is therefore seen of the lacquer and nearly always within a month. that the present phenomenon is entirely distinct Certain factors such as the acidity of the solvent from that of the gelation of bronzing lacquers employed, the amount of basic pigment incorand that the problem of eliminating this difli porated into the lacquer, the temperature, etc. culty has been solved by the unexpected disa will determine the speed at which gelation takes cover-y that small additions of malic acid or. a 7 place, but in any event, it will be found to occur salt of malic acid will prevent gelation or ag- 85 if these two constituents are present. glomeration.

For some time after the gel has first formed The lacquers in which malic acid or other it maybe destroyed by agitation, but after standsuitable malic acid derivatives can be successing for a period of a few weeks the gel will be fully used as the stabilizing agent may be any of found to be more permanent in nature. This the usual types in which basic pigments and 90 phenomenon is obviously very undesirable since esters of monohydroxy monocarboxylic acids are it inhibits brushability and necessitates high diemployed. The nitrocellulose may be the half lution with thinner before the lacquer maybe second type or other suitable low viscosity cottons employed. After gelation the lacquers are found such asiour second cotton. The usual plasticizto have poor flow, and the presence of agglomers such as dibutyl phthalate, tricresyl phosphate erates gives rise to an uneven film. 7 or castor oil may be used. Gums such as dam- Although many efforts have been made in'the mar, ester gum, elemi, or-synthetic resins may be past to avoid this difficulty which is encountered incorporated into the lacquers. The solvents may with lacquers of this type, such efforts until the consists solely of esters of monohydroxy monopresent time have met with failure. The surcarboxylic acids such as ethyl lactate, isopropyl prising discovery has now been made that the lactate, butyl lactate, secondary butyl lactate, addition of very small quantities of malic acid 1 amyl lactate, ethyl .oxyisobutyrate, etc., or may or salts of malic acid will obviate this difficulty. consist of mixtures of these compounds with other It has been found that in certain cases malic esters or with alcohols, glycols, ketones, ethers, acid or a salt of malic acid will prevent gelation .etc.- As examples of these latter compounds such or agglomeration of the lacquer. In general, an materials as ethyl acetate, butyl acetate, butyl addition of .1 %-1.5% of malic acid or a salt propionate, amyl acetate, acetone, diacetone alof malic acid will prevent gelling for a considcohol, monoethyl ether of ethylene glycol, monoerable length of time. For example, in laboratory butyl ether of ethylene glycol, ethyl alcohol, tests using various lacquers containing lactic butanol, or cyclohexanol may be used. If alcohols 1 acid esters and zinc oxide, those in which'.5% are used in Such miXtules y Serve dissolve the gums or to act as latent solvents. In V addition to the solvents, petroleum hydrocarbons Part8 such as naphtha or various gasoline fractions, Half second cotton 12 aromatic hydrocarbons such as benzol or toluol, Ester gum 9 or turpentine are usually employed to dissolve n f phosphate 6 gums and to serve as cheap diluents. oxlde 30 The malic acid or salt of malic acid is incor- Sodmm mala'te 3-1-5 porated t t lacquer generally in propor- In 100 parts of a solvent mixture consisting of: tions of from 1 to 20% of the weight of the cotton Pei-cent (.1%-1.5% of the total weight of the lacquer). Ethyl oxyisobutymte by voimgg In certain cases, for example when the amount of Butyl acetate 10 basic pigment employed isrelatively small, less Toluol 60 of the malic acid or its salt is required; and in other cases, for example when the acidity of the V P t at s gag s 13 ggg gg amounts of the acld or Half second cotton 12 Dammar 12 Examples Dibutyl phthalate s The following are type formula for lacquers f dloxlde containing basic pigments and esters of mono- 10 hydroxy monocarboxylic acids in which malic Mahc acld acid or a, alt of ali id i incorporated t In 100 parts of a solvent mixture consisting of prevent gelling, livering or agglomeration: Percent by volume I Butyl oxyisobutyrate 20 Parts Ethyl acetate 10 Half second cotton 12 Butyl acetate 10 Demmer 12 Toluol 60 2 22 2 1 22 thalate While the exact mechanism whereby malic acid Mane acid?1:321:31:3131:1333: .345 end vve eevvvevvvee evevevvv vhe eemee evevvee,

In 100 parts of a solvent mixture consisting of:

Percent by volume Ethyl lactate 20 Butyl acetate 10 Toluol '70 Parts Half second cotton 12 Ester gum 9 Tricresyl phosphate v 6 Zinc oxide Sodium malate 3-1.5

In 100 partsof a solvent mixture consisting of:

- Percent by volume Isopropyl lactate Xylol III Parts Half second cotton 12 Glyptal resin (Rezyl 12) 20 Dibutyl phthalate 3 Titanium dioxide 20 Zinc oxide 10 Malic acid .1 -.5

In 100 parts of a solvent mixture consisting of:

' Percent 1 by volume Isobutyl lactate 42 Naphtha (boiling range 140-190" C.) 58

Parts I-Ialf second cotton 12 Dammar 12 Dibutyl phthalate 8 Zinc oxide- 30 Malic acid- .31.5 In 100 parts of a solvent mixture consisting ofi:

Percent by volume Normal butyl lactate 37 Naphtha (boiling range ISO-200 C.) 63

or agglomeration of lacquers such as those illustrated by the above formulae is not known, it is probable that rather than entering into a chemical reaction, these compounds merely prevent the reaction product of the basic pigment and the acid radical of the solvent from assuming the physical state of a gel or of large agglomerates. This theory is substantiated in part by the fact that the gelation or agglomeration is prevented equally well by the free acid or by an alkaline salt such as sodium malate. The invention, however, is not to be construed as limited to any particular theory by which it may operate.

It is to be understood that while the invention is substantially described by the above disclosure and examples, it is not to be construed as limited to the use of the materials or combinations specifically named. Although zinc oxide was the only basic pigment specified in the examples, the invention is equally applicable to lacquers containing any other basic pigment such as, for example, certain grades of lithopone which have an alkaline reaction. Also, salts of malic acid other than sodium malate may be used, for example the potassium or lithium salts, and any mixtures of such compounds may also be used. For example, if an acid or alkaline reaction is undesirable, a neutral mixture of malic acid and an aling basic pigments and aliphatic estersof acids of the group consisting of lactic and hydroxy butyric acids which comprises adding to said lacquers at least one material selected from the group consisting of malic acid and salts of malic acid.

2. A method for preventing gelling, livering or agglomeration of nitrocellulose lacquers containing zinc oxide and an aliphatic ester of lactic acid which comprises adding to said lacquers at least one material selected from the group consisting of malic acid and salts of malic acid.

3. A method for preventing gelling, livering or agglomeration of nitrocellulose lacquers containing zinc oxide and an aliphatic ester of lactic acid which comprises adding to said lacquers .1 %-l.5% of at least one material selected from the group consisting of malic acid and salts of malic acid.

4. A method for preventing gelling, livering or agglomeration of nitrocellulose lacquers containing zinc oxide and an aliphatic ester of lactic acid which comprises adding malic acid to said lacquers.

5. A method for preventing gelling, livering or agglomeration of nitrocellulose lacquers containing zinc oxide and an aliphatic ester of lactic acid which comprises adding .1 %-1.5%' of malic acid to said lacquers.

6. A method for preventing gelling, livering or agglomeration of nitrocellulose lacquers containing zinc oxide and an aliphatic ester of lactic acid which comprises adding sodium malate to said lacquers.

'7. A method for preventing gelling, livering or agglomeration of nitrocellulose lacquers containing zinc oxide and an aliphatic ester of lactic acid which comprises adding .1 %1.5% of sodium malate to said lacquers.

8. A non-gelling non-agglomerating nitrocellulose lacquers which comprises nitrocellulose, a

9. A non-gelling non-agglomerating nitrocel- I lulose lacquer. which comprises nitrocellulose, zinc oxide, an aliphatic ester of lactic acid and at least one material selected from the group consisting of malic acid and salts of malic acid.

10. A non-gelling non-agglomerating nitrocellulose lacquer which comprises nitrocellulose, zinc oxide, an aliphatic ester of lactic acid and .1 %1.5% of at least one material selected from the group consisting of malic acid and salts of malic acid. 7

11. A non-gelling non-agglomerating nitrocellulose lacquer which comprises nitrocellulose, zinc oxide, an aliphatic ester of lactic acid and malic acid.

. 12. A non-gelling non-agglomerating nitrocellulose lacquer which comprises nitrocellulose, zinc oxide, an aliphatic ester of lactic acid and .1 %-1.5% of malic acid.

13. A non-gelling non-agglomerating nitrocellulose lacquer which comprises nitrocellulose,

zinc oxide, an aliphatic ester. of lactic acid and sodium malate.

g 14. A non-gelling non-agglomerating nitrocellulose lacquer which comprises nitrocellulose, zinc oxide, an aliphatic ester of lactic acid and .1 %-1.5% of sodium malate. 

